Inner-column-free rotary detonation combustion chamber based on central rotational flow

Abstract

The invention discloses an inner-column-free rotary detonation combustion chamber based on center rotational flow, and belongs to the technical field of detonation engines. Comprising a combustion chamber front wall face, an outer wall face, a center rotational flow air inlet system and an oil supply system. The combustion chamber is divided into an outer ring rotary detonation combustion area and a center rotational flow subsonic velocity combustion area. The outer ring area forms supersonic airflow through a Laval nozzle to be mixed with fuel, and detonation waves propagating in a self-sustaining mode are formed through ignition of a pre-detonation pipe. The central area generates a backflow area through a swirler, and fuel and air are fully mixed and then ignited by a sparking plug. The double combustion modes work cooperatively to adapt to different working conditions, and it is ensured that the combustion chamber operates stably under the wide-range condition. The design does not need inner column support, the structure is simplified, and the combustion efficiency and the working stability are improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of rotating detonation propulsion, and in particular relates to a rotating detonation combustion chamber without an inner column based on a central swirl. Background Art

[0002] With the development of the aerospace industry, the performance of traditional isobaric combustion has reached saturation, making it difficult to achieve significant improvements in propulsion efficiency. To further break through the combustion limits or energy utilization limits of aircraft engines, rotating detonation combustion has become the ideal combustion method for next-generation propulsion systems. The presence of the inner pillar in the traditional annular rotating detonation combustor poses additional challenges to the engine's thermal protection and weight reduction. To this end, a hollow barrel combustion chamber structure has been developed, which removes the inner pillar of the annular combustor. Compared with the annular combustor, the hollow barrel combustion chamber has a simpler structure and lower mass, which simplifies the cooling system of the inner pillar. The current operation of the rotating detonation combustor has high requirements for aerodynamic parameters and fuel supply parameters, and cannot cover the entire engine operating conditions from start-up to cruise. Therefore, one of the current major development directions is to achieve multi-mode coupled combustion of sub-combustion and detonation, as well as mode conversion, in the same configuration. Summary of the Invention

[0003] In order to realize the application of rotating detonation combustion chambers under different working conditions, the present invention provides a rotating detonation combustion chamber without inner column based on central swirl. By actively generating a recirculation zone, the interior of the combustion chamber is spatially partitioned to form a combustion mode of coupled sub-combustion and detonation, thereby realizing spatially partitioned combustion, thereby adapting to the full range of operating conditions from takeoff to cruising, and ensuring the stable operation of the combustion chamber under a wide range of conditions.

[0004] The technical solution to implement the present invention is: a central vortex-based inner column-free rotating detonation combustion chamber, including a coaxially arranged outer wall of the combustion chamber, a central vortex zone wall and a combustion chamber front wall, the combustion chamber front wall is fixed to the end of the central vortex zone wall, the central vortex zone wall is located inside the outer wall of the combustion chamber, the front end surfaces of the two are flush, and the cavity formed by the outer wall of the combustion chamber behind the front wall of the combustion chamber serves as the combustion chamber.

[0005] The annular cavity between the outer wall of the combustion chamber and the wall of the central swirl zone serves as the outer ring air intake system, which consists of the outer ring air intake, the Laval nozzle contraction section, and the Laval nozzle expansion section from front to back.

[0006] A plurality of through holes are evenly distributed along the circumferential direction on the middle section of the Laval tube expansion section as outer ring fuel inlets, and each outer ring fuel inlet is provided with an outer ring fuel supply nozzle.

[0007] The cavity in the wall of the central swirl zone serves as the central swirl intake system, which is divided into a central air inlet, a central air flow channel and a swirler from front to back. The swirler is fixed at the center of the front wall of the combustion chamber.

[0008] A central swirl oil supply system is provided in the inner cavity of the wall of the central swirl area, including a central fuel delivery pipe and a fuel nozzle connected in sequence from front to back. The central fuel delivery pipe is arranged along the central axis of the central air flow channel, and the fuel nozzle is set at the center position of the swirler.

[0009] Compared with the prior art, the present invention has the following significant advantages:

[0010] (1) The present invention relates to a central swirl-based, inner-column-free rotating detonation combustion chamber that utilizes a spatially partitioned combustion organization method. Through spatial partitioning, the combustion chamber is divided into an outer ring detonation combustion zone and a central swirl subsonic combustion zone. Independent central and outer ring air and fuel supply systems enable combustion under different operating conditions, ensuring stable operation of the aircraft under various operating conditions and improving combustion efficiency.

[0011] (2) The central swirl, inner column-free rotating detonation combustion chamber of the present invention utilizes the high cycle efficiency of detonation combustion by partitioning the combustion chamber in space, and at the same time solves the problem of wide-range operation of the engine from ground aerodynamics to cruise under a single configuration, thereby promoting the engineering application of detonation combustion. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 This is a combustion chamber structure diagram of the central swirl-based inner-column-free rotating detonation combustion chamber of the present invention.

[0013] Figure 2 This is a schematic diagram of the flow characteristics of the inner-column-free rotating detonation combustion chamber based on central swirl according to the present invention.

[0014] Figure 3 This is the flow field diagram of the central swirl-based inner-column-free rotating detonation combustion chamber of the present invention.

[0015] Explanation of the reference numerals: outer ring air inlet 1, Laval nozzle contraction section 2, central swirl zone wall 3, outer ring fuel inlet 4, Laval nozzle expansion section 5, combustion chamber front wall 6, combustion chamber outer wall 7, central air inlet 8, central fuel delivery pipe 9, central air flow channel 10, fuel nozzle 11, swirler 12, pre-detonation tube 13, spark plug 14, outer ring air 15, outer ring fuel 16, central swirl air 17, central reflow subsonic combustion zone 18, rotating detonation zone 19, central reflow zone fuel 20, outer ring fuel-air mixture flow 21, central swirl zone fuel-air mixture flow 22, detonation wave 23, reflow vortex 24. DETAILED DESCRIPTION

[0016] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0017] It should be noted that, when describing the detonation combustion chamber structure of the present invention, the terms "front," "rear," "circumferential," "inner," and "outer," etc., refer to positions or relative positions in the accompanying drawings. These terms are used solely to simplify the description of the present invention and do not imply that the device or components described must maintain the specific positions, structures, or operations described. Certain components may be omitted, enlarged, or reduced in size in the drawings, and do not represent the dimensions of the actual product. Therefore, they should not be construed as limitations of the present invention.

[0018] In the present invention, unless otherwise specified or limited, the terms "connection" and "fixation" should be understood in a broad sense. For example, "fixation" can refer to fixed connection, detachable connection, or integration; "connection" can refer to mechanical connection or electrical connection. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0019] In addition, the technical solutions between the various embodiments of the present invention can be combined with each other, but it must be based on the fact that ordinary technicians in this field can implement it. When the combination of technical solutions is mutually contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0020] The following will further introduce the specific implementation methods, as well as the technical difficulties and inventive points of this invention in combination with this design example.

[0021] The present invention proposes a central swirl-based, inner-column-free rotating detonation combustion chamber, which adopts a combustion scheme based on the central swirl and the mainstream detonation, and aims to replace the traditional rotating detonation combustion chamber. Specifically, the airflow passes through the central air flow channel 10, and forms a recirculation vortex 24 under the forced flow of the swirler 12. Among them, by arranging the swirler 12 in the center, the flow structure of the recirculation vortex 24 is guaranteed to be stable in the absence of an inner column, thereby realizing the subsonic combustion and detonation combustion partitioning combustion mode. Here, subsonic combustion is carried out in the central recirculation subsonic combustion zone 18, and rotating detonation combustion is carried out in the rotating detonation zone 19. The combustion chamber does not require inner column support, the structure is simplified, and the combustion efficiency and working stability are improved. The combustion chamber adapts to different working conditions by independently regulating the oil and gas in the central recirculation subsonic combustion zone 18 and the rotating detonation zone 19, effectively widening the stable working range of the combustion chamber.

[0022] Combine Figures 1 to 3 A central swirl-based inner column-free rotating detonation combustion chamber comprises a coaxially arranged combustion chamber outer wall 7, a central swirl zone wall 3 and a combustion chamber front wall 6. The combustion chamber front wall 6 is fixed to the end of the central swirl zone wall 3. The central swirl zone wall 3 is located inside the combustion chamber outer wall 7. The front end surfaces of the two are flush. The cavity formed by the combustion chamber outer wall 7 behind the combustion chamber front wall 6 serves as the combustion chamber.

[0023] The annular cavity between the outer wall surface 7 of the combustion chamber and the wall surface 3 of the central swirl zone serves as the outer ring air intake system, which includes, from front to back, the outer ring air intake 1, the Laval nozzle contraction section 2, and the Laval nozzle expansion section 5.

[0024] A plurality of through holes are evenly distributed along the circumferential direction on the middle section of the Laval tube expansion section 5 as outer ring fuel inlets 4 , and each outer ring fuel inlet 4 is provided with an outer ring fuel supply nozzle.

[0025] The cavity within the central swirl zone wall 3 serves as a central swirl intake system, which is divided from front to back into a central air inlet 8, a central air flow channel 10 and a swirler 12. The swirler 12 is fixed at the center of the front wall 6 of the combustion chamber.

[0026] A central swirl oil supply system is provided in the inner cavity of the central swirl zone wall 3, including a central fuel delivery pipe 9 and a fuel nozzle 11 connected in sequence from front to back. The central fuel delivery pipe 9 is arranged along the central axis of the central air flow channel 10, and the fuel nozzle 11 is set at the center position of the swirler 12.

[0027] The outer ring rotating detonation combustion chamber realizes a circumferentially rotating detonation wave 23 near the outer wall surface 7 of the combustion chamber without an inner column.

[0028] The outer ring air 15 of the combustion chamber enters the outer ring air intake system through the outer ring air inlet 1, forms a supersonic airflow after passing through the Laval nozzle contraction section 2 and the Laval nozzle expansion section 5, and the outer ring fuel 16 is injected from the outer ring fuel inlet 4 and is fully mixed with the outer ring air 15 in the Laval nozzle expansion section 5 to obtain the outer ring fuel-air mixed airflow 21 and then enter the rear combustion chamber.

[0029] After the outer ring fuel-air mixture flow 21 enters the combustion chamber, it is detonated by the pre-detonation tube 13 placed on the outer wall 7 of the combustion chamber in the detonation combustion zone and generates a self-sustaining rotating detonation wave 23, forming an outer ring rotating detonation zone 19.

[0030] The outer ring fuel supply nozzle on the outer ring fuel inlet 4 includes but is not limited to a centrifugal nozzle, a pneumatically assisted nozzle, a straight-injection nozzle, a dual-path centrifugal nozzle, and a solid nozzle.

[0031] The outer ring fuel 16 includes gaseous and liquid fuels.

[0032] The central swirl air 17 provided by the external compressor enters the central swirl intake system through the central air inlet 8, flows through the central air flow channel 10 and enters the swirler 12, forming a recirculation vortex 24 behind the front wall 6 of the combustion chamber, and the recirculation vortex 24 stabilizes the subsonic flame.

[0033] The central recirculation zone fuel 20 provided by the external fuel supply system passes through the central fuel delivery pipe 9 and is injected by the fuel nozzle 11 placed in the center of the swirler. The fuel is mixed with the air passing through the swirler 12 to form a central swirling zone fuel-air mixed flow 22, and is further mixed in the rear recirculation vortex 24. The central swirling zone fuel-air mixed flow 22 is ignited by the spark plug 14 placed on the rear end surface of the front wall surface 6 of the combustion chamber, thereby realizing subsonic combustion in the central recirculation zone, thereby forming a central recirculation subsonic combustion zone 18 after the swirler (12).

[0034] Cyclones include, but are not limited to, primary, secondary, and tertiary cyclones.

[0035] The central reflow subsonic combustion zone 18 is coaxial with the rotating detonation zone 19 , and the rotating detonation zone 19 surrounds the central reflow subsonic combustion zone 18 .

[0036] The innovation of the present invention's central swirl-based, inner-pillar-free rotating detonation combustion chamber lies in the absence of an inner pillar. By spatially partitioning the combustion area, a central recirculating subsonic combustion zone 18 and a rotating detonation zone 19 coexist without an inner pillar. Independently regulating the oil and gas flow in the central recirculating subsonic combustion zone 18 and the rotating detonation zone 19 allows for adaptation to diverse operating conditions, effectively expanding the combustion chamber's stable operating range.

Claims

1. A central swirl-based rotating detonation combustion chamber without an inner column, characterized in that: The combustion chamber comprises a coaxially arranged outer wall surface (7), a central swirl zone wall surface (3), and a combustion chamber front wall surface (6), wherein the combustion chamber front wall surface (6) is fixed to the end of the central swirl zone wall surface (3), and the central swirl zone wall surface (3) is located inside the combustion chamber outer wall surface (7), and the front ends of the two are flush with each other, and the cavity formed by the combustion chamber outer wall surface (7) behind the combustion chamber front wall surface (6) serves as the combustion chamber; The annular cavity between the outer wall surface (7) of the combustion chamber and the wall surface (3) of the central swirl zone serves as an outer ring air intake system, which comprises, from front to back, an outer ring air intake (1), a Laval nozzle contraction section (2), and a Laval nozzle expansion section (5); A plurality of through holes are evenly distributed along the circumference of the middle section of the Laval tube expansion section (5) as outer ring fuel inlets (4), and each outer ring fuel inlet (4) is provided with an outer ring fuel supply nozzle; The cavity in the central swirl zone wall (3) serves as a central swirl intake system, which is divided from front to back into a central air inlet (8), a central air flow channel (10) and a swirler (12), and the swirler (12) is fixed at the center of the front wall (6) of the combustion chamber; A central swirl oil supply system is provided in the inner cavity of the wall surface (3) of the central swirl zone, comprising a central fuel delivery pipe (9) and a fuel nozzle (11) connected in sequence from front to back. The central fuel delivery pipe (9) is arranged along the central axis of the central air flow channel (10), and the fuel nozzle (11) is arranged at the center of the swirler (12).

2. The central swirl-based inner-column-free rotating detonation combustion chamber according to claim 1, characterized in that: The outer ring rotating detonation combustion chamber realizes a circumferentially rotating detonation wave (23) near the outer wall surface (7) of the combustion chamber without an inner column.

3. The central swirl-based inner-column-free rotating detonation combustion chamber according to claim 2, characterized in that: The combustion chamber outer ring air (15) enters the outer ring air intake system through the outer ring air inlet (1), forms a supersonic airflow after passing through the Laval nozzle contraction section (2) and the Laval nozzle expansion section (5), and the outer ring fuel (16) is injected from the outer ring fuel inlet (4) and fully mixed with the outer ring air (15) in the Laval nozzle expansion section (5) to obtain an outer ring fuel-air mixed airflow (21) and then enters the rear combustion chamber.

4. The central swirl-based inner-column-free rotating detonation combustion chamber according to claim 3, characterized in that: After the outer ring fuel-air mixed air flow (21) enters the combustion chamber, it is detonated by the pre-detonation tube (13) placed on the outer wall (7) of the combustion chamber in the detonation combustion zone and generates a self-sustaining and propagating rotating detonation wave (23), forming an outer ring rotating detonation zone (19).

5. The central swirl-based inner-column-free rotating detonation combustion chamber according to claim 3, characterized in that: The outer ring fuel (16) includes gaseous and liquid fuels.

6. The central swirl-based inner-column-free rotating detonation combustion chamber according to claim 1, characterized in that: The outer ring fuel supply nozzle on the outer ring fuel inlet (4) includes but is not limited to a centrifugal nozzle, a pneumatically assisted nozzle, a direct injection nozzle, a dual-path centrifugal nozzle, and a solid nozzle.

7. The central swirl-based inner-column-free rotating detonation combustion chamber according to claim 1, characterized in that: The central swirl air (17) provided by the external compressor enters the central swirl intake system through the central air inlet (8), flows through the central air flow channel (10) and enters the swirler (12), and forms a recirculation vortex (24) behind the front wall (6) of the combustion chamber, and the subsonic flame is stabilized by the recirculation vortex (24).

8. The central swirl-based inner-column-free rotating detonation combustion chamber according to claim 7, characterized in that: The central recirculation zone fuel (20) provided by the external fuel supply system passes through the central fuel delivery pipe (9) and is injected by the fuel nozzle (11) placed at the center of the swirler. The fuel is mixed with the air passing through the swirler (12) to form a central swirling zone fuel-air mixed flow (22), which is further mixed in the rear recirculation vortex (24). The central swirling zone fuel-air mixed flow (22) is ignited by the spark plug (14) placed on the rear end surface of the front wall surface (6) of the combustion chamber, thereby realizing subsonic combustion in the central recirculation zone and forming a central recirculation subsonic combustion zone (18) behind the swirler (12).

9. The central swirl-based inner-column-free rotating detonation combustion chamber according to claim 8, characterized in that: The cyclones (12) include, but are not limited to, primary, secondary and tertiary cyclones.

10. The central swirl-based inner-column-free rotating detonation combustion chamber according to claim 4 or 8, characterized in that: The central reflow subsonic combustion zone (18) is coaxial with the rotating detonation zone (19), and the rotating detonation zone (19) surrounds the central reflow subsonic combustion zone (18).

Images